Authentic Spanish Tortilla: Traditional Egg and Potato Recipe

A Spanish tortilla is a cross between an omelet and a frittata. Thinly sliced potatoes and onions are gently fried in plenty of olive oil until tender, then bound with eggs to create a firm, layered cake that’s delicious hot or at room temperature. It’s simple to make and full of comforting flavor.

I learned this recipe from a Spanish exchange student who became family years ago. The first time she served tortilla, it surprised us — its texture and flavor are different from a typical frittata and much more satisfying. Her main tip was clear: fry the potatoes in plenty of oil to get the right texture and flavor.

🥘 Ingredients Needed

• Sliced potatoes (Yukon Gold or Russet recommended)
• Extra virgin olive oil
• Eggs
• Diced onion
• Kosher salt
• Ground black pepper

🍽 Equipment Needed

• a 10–12 inch cast-iron or oven-safe pan
• a mandoline slicer or a very sharp knife
• a rubber spatula
• a large, flat plate for flipping
• a large bowl
• a strainer or colander
• a slotted spatula or slotted spoon

🥣 How to Make a Spanish Tortilla

Making a Spanish tortilla is straightforward but requires a bit of patience while frying the potatoes. Follow these steps for a reliably layered, tender result.

STEP 1: Prepare the vegetables.

Dice the onion and thinly slice the potatoes. Peeling the potatoes is optional but often preferred. Aim for slices about 1/8 to 1/4 inch thick. A mandoline speeds this up, but a sharp knife works fine — take care.

STEP 2: Heat the oil and preheat the oven.

Warm a generous amount of olive oil over medium heat and preheat your oven to 350°F (175°C). You’ll shallow-fry the potatoes, so the oil level should cover at least half the thickness of the slices.

STEP 3: Fry the potatoes and onions.

When the oil is hot, fry the potatoes and onions in batches so they can cook evenly. Test the oil by dropping a single potato slice in — it should sizzle gently. Season each batch with a pinch of salt and pepper while frying.

As each batch finishes, drain it in a colander set over a bowl to catch the oil for reuse. When you start the final batch, whisk the eggs in a bowl with the remaining salt and pepper.

STEP 4: Drain most of the oil from the pan.

After frying all the potatoes and onions, pour off the excess oil (reserve a few tablespoons for cooking the tortilla). Return the pan to the heat.

STEP 5: Assemble and cook the tortilla on the stove.

Add a tablespoon or two of the reserved oil to coat the pan. Spread the cooked potatoes and onions evenly so they lie flat. Pour the beaten eggs over the top and let the mixture set on the edges for a few minutes. Use a rubber spatula to loosen the edges, then lower the heat and cook 5–7 minutes on low to medium-low until the underside is set.

STEP 6: Flip the tortilla.

Place a large flat plate over the pan, invert the pan so the tortilla drops onto the plate, then slide it back into the pan, uncooked side down. Do this over a sink in case oil drips.

STEP 7: Finish in the oven and rest.

Cook the second side for 2–3 minutes on the stove, then transfer the skillet to the preheated oven for about 5 minutes to ensure the center is fully set. Remove, slide the tortilla onto a cutting board, and let it cool for a few minutes before slicing.

A properly cooked tortilla shows visible layers of potatoes and onions bound by a tender egg interior.

🍳 Serving Suggestions & Uses

Slice the tortilla into wedges and serve it at breakfast, brunch, lunch, or dinner. In Spain it’s common as tapas, but it also works as a main course alongside roasted or steamed vegetables. Serve warm or at room temperature; a sprinkle of flaky sea salt on top brightens the flavors.

🍲 Serving Size

Cut into eight wedges like a pie. Each slice makes a satisfying portion for most meals. Leftovers are great cold or reheated.

🥫 Storage/Shelf Life/Reheating

• In Spain, tortilla is often kept at room temperature. In the U.S., store in an airtight container in the refrigerator because of egg safety—keeps about a week.
• Portions freeze well for up to 6 months. Thaw completely before reheating.
• Reheat gently in a toaster oven, air fryer, or conventional oven at 300–350°F for a few minutes to avoid rubbery eggs; avoid the microwave if possible.

✏️ Helpful Tips

• Ventilate the kitchen while frying; the process creates a strong fried aroma.
• Use the mandoline guard to protect your hands when slicing potatoes.
• Test oil temperature by dropping in a potato slice—if it bubbles, it’s ready.
• Flip the tortilla over a sink to catch any stray oil and avoid mess.
• When reheating, prefer oven methods over the microwave to preserve texture.